User ID: 7399413
|Sep 27th 3:59 PM
I have an 89 allegro 27' on a p30 chasis. it is stock, haven't done anything to
suspension yet. This thing goes down the road like a boat and rolls and leans as you
go. I need to tighten it up. I plan to put on bilsteins but what else should I do to
tighten up. Has original tires which I will replace-any thoughts on a type that might
help this problem?
||Sep 27th 4:10 PM
We used to have the same problem with our 34' Class A MH. In addition, we were buffeted
all over the road by passing big rigs. It was no fun!
We solved those problems by switching to Bilstein shocks, correctly inflated
Bridgestone tires, and by making sure that our air bags had the correct amount of air
for the weight of our rig.
Now, our ride is smooth, comfortable, and my knuckles seldom turn white.
Remember, others have their preferences, they may be different than ours, but the
changes worked for us.
||Sep 27th 4:51 PM
Just a quick postscript to my previous message;
If your tires are truly 11 or 12 years old please don't wait too long to replace them.
They've already put in twice the recommended number of years of service and are
seriously dangerous to drive on.
User ID: 0359544
|Sep 27th 6:17 PM
Take a look under your chassis and see if you have anti-sway bars FRONT & REAR, if
not it would be a good $100-125 + labor to have these at both ends. Even if you do you
might want to check on larger ones. Controls sway without stiffening anything while
User ID: 0310794
|Sep 27th 9:21 PM
I to have a 89, A holiday rambler on a p-30.
When I got it there were the original tires On it.
It drove and acted like you say. The first thing I Did was put on new Bridgestone
Tires, And 90% of the rolling went away. Bilsteins are next.
User ID: 1516194
|Sep 27th 11:02 PM
Jim, I second Mile's comments on the age of your tires. Look at the sidewalls and if
you see cracking/weather checking, get them off your rig as soon as possible. I bought
a '94 with only 31,000 miles and great thread (that looked like they would go 80-90,000
miles) but they were checking/cracking. I checked the date code numbers and found that
the tires were manufactured the 33rd week of 1993, so they were over 6.5 years old.
When I found that out, the tires were gone that weekend. If the tires are steadily used
they last longer and get those total miles, but when they sit, they don't flex. Flexing
is what keeps the rubber 'young'.
ipd (http://www.ipdusa.com/suspension/class_a_motorhomes.html ) makes heavy duty front
sway bars for the P30, that run $225 to $255 plus shipping and installation.
User ID: 3710164
|Sep 27th 11:14 PM
Hi folks, I was reading this thread with interest 'cause I may have the same issue
of old tires. The tires have small cracks. How do I read the date code the Fred talked
User ID: 1516194
|Sep 28th 0:31 AM
I was afraid that someone would ask, but I could not remember the exact sequence, so
I had to sort through my Hotlist (bookmarks) to find the source.
The following quote is from: http://www.michelin.com/us/eng/tire/guide/lesson4.html
Essentially the DOT marking serves as the tire's fingerprint. DOT signifies that the
tire complies with U.S. Department of Transportation Tire Safety Standards, and is
permitted for highway use. For example refer to the following markings: DOT M5H3
459X 064. The first letter and number following DOT designate the tire's manufacturer
and plant code. The third, fourth and fifth number and letter, 59X, is the tire size
code which is an optional manufacturers code that identifies the tire size and other
specific characteristics of the tire. The final three numbers denote when the tire was
produced, with the first two indicating the week, and the last number indicating the
year (064 indicates the tire was built in the 6th week of 1994)."
Since no tire should be out there that is over 10 years old, the one digit field for
the year is O.K.
||Sep 28th 9:28 AM
Re. Fred's comment - "Since no tire should be out there that is over 10 years old,
the one digit field for the year is O.K."
Jim's tires are probably going to have DOT date codes of something like XX8 or XX9. If
he didn't already know that the tires were original he might assume that they were made
in '98 or '99 rather that '88 or '89. In some cases those tires could actually be from
The DOT is aware of the problem, and so are the manufacturers, but no one is doing
anything to change it.
Consumer beware. When in doubt, INSPECT. If still in doubt, REPLACE!
User ID: 0025534
|Sep 28th 12:02 PM
Read through this thread with much interest.
mentioned air bag inflation pressure. Where do you find the correct pressure for the
front air bags?
The small manual that came with the P-30 says at least 60 lbs but not how much above
that or some kind of chart to follow.
I have a 1984 Winnebago on a P-30 chassis.
Another question where do you find the recommended tire pressure for Bridgestone
Have gone to the web and Bridgestone/Firestone and could not find a chart that showed
tire size, vehicle weight and pressure recommended.
Should the tire side walls bow out or should the pressure be high enough to keep the
side walls from bowing out? The 8R19.5 duals seem to bow out more than my front 245 R70
I installed Bilsten shocks all way around and a IPD front sway bar, plus the neopreme
mounts for the original rear sway bar. On the older P-30 chassis, I had to have the
rear shock frame mounts welded as they are only spot tacked and the Bilsten shocks
apply to much force and tend to break the mounting bolt where it mounts to the
The rear bar is 1.75 diameter and plenty stiff. The old front sway bar is 1.25 inches
diameter and the IPD bar is 1 5/8 inches diameter. Does not sound like much, but it
sure is bigger and heavier.
I feel any RV with a basement needs the IPD sway bar. This type RV is higher and has
more weight in the upper part of the vehicle. This creates more upper forces as you
turn at highway speeds.
I see RV's going down the road leaning to one side. I feel this affects ride and
handling is this true?
I keep my RV level. Use the front and rear air bags to compensate for lean. Some time I
have to shift personal items to level out.
Please pass on any thoughts or ideas.
||Sep 28th 12:41 PM
The Bridgeston truck tire inflation guide can be found at http://www.trucktires.com/ .
Click on 'Technical Information' and then on 'Load/Inflation Tables'.
Of value also is the Bridgestone Tire and Wheel Primer at
http://www.trucktires.com/techinfo.htm . You can find a load/inflation table from there
The Michelin load/inflation guide can be found at http://188.8.131.52/truck/rv.htm .
Just pick your tire from the several selections and then go to 'Load &
P-30 air bag pressure: We discussed this at some length here about a year or so ago.
Although none of us could find a GM air bag inflation guide we were able to come up
with the following on our own:
16,000# GVWR chassis = 5,500# front axle = 90 psi
14,800# GVWR chassis = 5,300# front axle = 70 psi
14,500# GVWR chassis = 5,000# front axle = 50 psi
12,300# GVWR chassis = 4,300# front axle = 40-50 psi
Rear air bag air pressures were not specifically determined but, if I remember
correctly, we decided that the best thing to do was to start with the same psi as the
fronts and then adjust upward on each side for level and best ride.
Installing Bilstein shocks on older P-30 chassis; Yes, it is necessary to weld the new
rear shock mounts, just as William found. This information is provided by Bilstein in
their instructions and is a normal requirement for the more heavy duty shock.
Radial tires do have more sidewall "bow" (flex) than bias ply tires. Weighing your rig
and adjusting the air pressure accordingly will assure proper inflation. Different tire
brands and sizes may well show a different "bow" even at the same air pressure.
Different ply ratings will make the effect even more noticeable.
Lord, it's amazing what you can learn on the True RVer's Forum!
User ID: 0025534
|Sep 29th 6:19 AM
Thanks ever so much for the tire and air bag information. What ever did we do before
this bulletin board and the internet.
Keep up the good work.
When your new to Rving and Class A motorhomes. You have many questions.
Thanks again !!!
User ID: 1516194
|Sep 29th 10:39 AM
Mike has a good point in that I forgot about tires made in the19'80's. They
shouldn't be out there, but there will someone who doesn't know the true age of a tire.
I didn't know how to determine that at first. Once I did, those tires came off - fast.
Mike's last comment is the most important of all ---INSPECT. Some tires will age faster
than others, depending on a lot of things, so above all else look for cracking , wear
These BBS's are great in getting and passing along knowledge.
||Oct 6th 7:20 AM
I too am new to MH RVing and just purchased a 2000 Georgie Boy Pursuit 35.5'. It
leans to the right (slightly) while driving on supposedly level road. I am aware of the
air bags but the documentation (user's manuals etc.) does NOT indicate air bag pressure
or how to manipulate it. How do you measure the air bag pressure? How do you adjust it?
I'm really at a loss with this one.
||Oct 6th 11:29 AM
Congratulations on your new Georgie Boy, and welcome to The True RVer's Forum!
Here's my best advice; Go back to the dealer you bought your new MH from and ask them
to give you a COMPLETE tour of your rig. If they won't do it, or if they act like it's
an inconvenience, then you can prepare yourself for a lot of disappointment with
Before you ever drove your new rig off of their lot they should have taken you through
it and shown you how to operate everything, both inside and out . . . to include how
and where to fill your airbags.
Since there are several different ways to adjust the air pressure, and many different
locations the valve could be located, I'll leave that answer to your dealer or one of
our kindly Georgie Boy owners.
User ID: 0631424
|Oct 7th 6:19 PM
Dave could some of that leaning be perception? You are a lot higher above the road
than you sed to be. Even 'level' roads are crowned in the center to help water run
Beyond that what Mike says is very true. Since I own a very old Class A I have no one
to lean against...YOU however just dropped a big chunk of change in thier
||Dec 3rd 7:32 PM
Have Allegro '84 12800 gvw. 27 ft. Owners manual (from Tiffin) states as follows:"
Air Bags- Air pressure may be increased or decreased to adjust vehicle trim and
minimize crash through on large road bumps or depths. Inflation pressure must be
maintained between 50 psi min. and 75 psi Maximum. Failure to maintain air in in the
bags will result in an out of alignement condition and will cause the front tires to
wear out in about 2000 miles". The word "depths" seemingly has no meaning in this
instance. I run Bridgestone 230 Vsteels at 70 psi. Handles well. Hope this helps.
User ID: 9454293
|Jan 18th 0:49 AM
Mike, I knew I had asked this question but I read a number of Forums and didn't find
this until now. I have an appointment with the dealer tomorrow and I don't think he
realizes how busy he is going to be. Thanks for the info. My dealer has really been
super - so far. A number of little things and she took care of them all in a very
expeditious manner. This question is the only one I still have open and will get it
answered "post haste". Thanks again.
||Jan 24th 4:43 PM
I have a 1986 Triple EEE class C motorhome on a Ford F-350 chassis with 109,000 kms.
I get a terrible bang/thump from the rear when i go over bumps or potholes on the road
at any speed other than dead slow. I have replaced the shocks, i'm wondering weather
the springs are shot or would
airbags solve my problem.
Thanks for any help.
||Jan 24th 4:45 PM
On that age coach, the prings are probably sagging pretty badly. From my experience,
Ride-Rite rear bags will help, but is not a 100% fix. How much longer do you plant to
keep the coach? If for more than a couple of years, it may be time to put on new
springs(and shocks) front and rear.